1. Field of the Invention
The present invention relates to a vacuum transistor having an optical gate and a method for manufacturing the same, and more particularly to a vacuum transistor in which an electric field is applied to two adjacent electrodes under a vacuum state or an atmosphere state and photons having a threshold energy or more are radiated from an optical gate to one of the electrodes so as to emit electrons therefrom and a manufacturing method of the vacuum transistor with an optical gate.
2. Description of the Prior Art
Recently, electric devices have further developed in accordance with the development of solid semiconductor physics, and in such electric devices enhancement of high speed, high integration, high reliability or the like is more continuously required.
The continued development of such an electric device has been limited by minutely working techniques, and therefore there arise various obstacles in manufacturing of this electric device.
Particularly, in fabrication of solid state electric devices the mobility of respective electrons flowing in the respective devices becomes a significant physical factor determining electrical characteristics of such semiconductor devices, electric materials and the like, because transference of the respective electrons is determined by a scattering phenomenon as is well-known in this art.
When a silicon substrate is utilized in fabrication of such transistors, mobility of electric charges in the silicon substrate is determined previously and therefore the performance of the respective transistors is also determined.
FIG. 1 is a sectional view showing the construction of a conventional MOS (metal oxide semiconductor) transistor using a silicon substrate. In FIG. 1, reference numeral 5 represents a silicon substrate, 2 and 3 represent source and drain regions, respectively, and 1 represents a gate electrode formed on the substrate 5 between the regions 2 and 3. Between the gate electrode 1 and the substrate 5 is formed a gate insulating layer 4.
In the operation of such a conventional MOS transistor, the silicon substrate 5 serves only as support means, and the transferring of electrons is substantially carried out in the gate electrode 1 and in a channel region of the substrate 5 which is formed beneath the gate insulating layer 4.
To overcome those limits with respect to mobility of electrons in the solid state channel region of the transistor as shown in FIG. 1, it is required that electrons are transferred in a vacuum state or an atmosphere state channel of such a transistor without reference to the above-mentioned scattering and the mobility of electrons therein is determined only by an externally applied electrical field, thereby obtaining characteristics of a high-speed operation.